As found on Baltimore trim tags, this number ranges from 001...999 then
starts over with 001. This is believed to be an internal number used to
track the particular interior work and aside from being found on the
trim inspection sheet has no significance today.

As found on Fremont tags, this number is typically a 2-digit number
with the two digits separated by a dash character such as 5-2
although some later builds have a 2-digit number without the dash
character.